Note: category suggestions from Flickr tags are not easy.

• Must resolve redirects, both soft and hard. At the Commons, soft redirects are categories that themselves are in Category:Category redirects.
• Should not suggest disambiguation categories (at the Commons: categories that are themselves in Category:Disambiguation)
• Should not suggest top-level categories (at the Commons: categories that themselves are in Category:Categories requiring permanent diffusion)
• Must not suggest duplicates

Flinfo does all this; see its FlinfoWiki class. That still doesn't guarantee that categories generated from Flickr's tags are always good, but it avoids the worst blunders.

Forgot one thing: must not suggest non-existing categories. An example would be Category:Beach from the tag "Beach" on the sample image given above. Commons has no such category.

Marking as low priority and enhancement as Flickr upload has some other bugs to be fixed before this.